Geophysical surveys are often used for oil and gas exploration in geophysical formations, which may be located below marine environments. Various types of signal sources and geophysical sensors may be used in different types of geophysical surveys. Seismic geophysical surveys, for example, are based on the use of seismic waves. Electromagnetic (EM) geophysical surveys, as another example, are based on the use of EM fields. In some surveys, a survey vessel may tow one or more sources (e.g., air guns, marine vibrators, electromagnetic sources, etc.) and one or more streamers (e.g., seismic streamers or electromagnetic streamers) along which a number of sensors (e.g., hydrophones and/or geophones and/or EM sensors) are located.
In the example of EM surveying, EM fields generated by an electronic source such as a dipole source may be transmitted through the water and into the earth's crust, and then reflected back and captured at the towed sensors along the streamers to detect resistive features or anomalies. Data collected during a marine geophysical survey may be analyzed to locate hydrocarbon-bearing geological structures, and thus determine where deposits of oil and natural gas may be located.
Various safety issues involving electrical faults may arise in the use of streamers such as EM streamers. Embodiments of this disclosure may be used to address some of such safety issues, as discussed below.